Links
GNU Radio
Overview: https://wiki.gnuradio.org/index.php/Main_Page
Installation: https://wiki.gnuradio.org/index.php/InstallingGR
HackRF
HackRF Depo: https://github.com/mossmann/hackrf
Portapack: https://github.com/sharebrained/portapack-hackrf
Using HackRF: https://greatscottgadgets.com/sdr/